1. Field of the Invention
This invention relates generally to improvement in the coating of cables, and more particularly, but not by way of limitation, to an improved apparatus for applying a liquid coating material to the exterior of an electrical coaxial cable or the like.
2. Description of the Prior Art
In the telephone industry it has become commonplace to periodically apply a liquid coating material to the exterior of old telephone cables to maintain or improve the water resistant insulation characteristics of these cables. Conventional telephone coaxial cables are sheathed with lead to provide protection for the individual electrical conductors disposed therein. Through long periods of exposure to the elements and through the attack by squirrels, the lead sheathing often is afflicted with cracks or holes therein which permits the entrance of moisture into the coaxial cable which, in turn, causes shorting among the individual electrical conductors therein. Microscopic cracks form in the lead sheathing through prolonged exposure of the cable to the elements. Much larger holes in the lead sheathing can be attributed to the knawing of squirrels on the lead sheathing.
In view of this deterioration that appears in the lead sheathing of telephone cables, it has become economically feasible to periodically apply an insulating coating to the exterior of such cables rather than to replace cables with newer, better insulated cables. One such technique which has gained widespread approval embodies the application of a liquid coating material called "Insalite" which is manufactured and sold by Winton Products Co., Inc. of Charlotte, North Carolina. Various techniques have been employed to apply this liquid coating material to the exterior of telephone cables. Most obviously, hand application has been employed to a limited degree in areas where it would be most disadvantageous for the liquid coating material to fall on structures or foliage adjacent the work site. Another technique embodies the manual application of the liquid coating material by means of a roller sprayer having two or more spray nozzles which can be manipulated and propelled manually from the ground to traverse along the cable by means of a conventional utility stick. Pressurized liquid coating material is provided to the spray head through a conduit connected to a pressure tank on the operator's back at the ground level. More recently, an engine-powered pump has been utilized on the ground to provide pressurized liquid coating material to the spray head being manipulated along the cable.
In contrast, the apparatus of the present invention overcomes all the disadvantages of the prior art apparatus and techniques and permits the economical, uniform and neat application of liquid coating material to the exterior of telephone cables or other elevated cables without manual manipulation and propulsion of the apparatus during traverses along the cable.
The present invention contemplates an apparatus for dispensing a coating of liquid on a telephone cable or the like supported above the ground which apparatus includes a frame, and support means carried on the frame for supporting the apparatus on a cable for movement of the apparatus therealong. The apparatus further includes liquid supply means carried by the frame for providing a quantity of liquid under elevated pressure, and nozzle means carried by the frame and communicating with the liquid supply means for receiving liquid therefrom and directing liquid onto a cable. The apparatus also includes drive means carried by the frame and operatively connected to the support means for propelling the apparatus along the cable upon which it is supported.
An advantage of the invention is the provision of the apparatus which provides increased efficiency in the maintaining of telephone cables or the like.
Another advantage of the present invention resides in the provision of a self-propelled apparatus for dispensing a coating of liquid on a telephone cable or the like supported above the ground which is unaffected by terrain features beneath the cable.
A further advantage of the present invention resides in the provision of an apparatus which minimizes the possibility of overspraying liquid coating material onto adjacent foliage and structures during the coating of a length of telephone cable or the like.
A still further advantage of the present invention resides in the provision of an apparatus for dispensing coating liquid on a telephone cable or the like supported above the ground which employs the liquid coating material as the hydraulic fluid in the drive mechanism of the apparatus.
A yet further advantage of the present invention resides in the provision of apparatus for uniformly dispensing a coating of liquid on a telephone cable or the like supported above the ground which is light in weight, economical in construction and operation, and simple to operate and maintain.
Further objects and advantages of the present invention will be evident from the following detailed description when read in conjunction with the accompanying drawings.